Heat operated refrigeration apparatus having device utilizing flue gas for returning condensate



May 31, 1955 w. M. SIMPSON 2,709,347

HEAT OPERATED REFRIGERATION APPARATUS HAVING DEVICE UTILIZING FLUE GASFOR RETURNING coNDENsATE Filed March 1, 1952 HEAT OPERATED REFRIGERATIONAPPARATUS HAVING DEVICE UTILIZING FLUE GAS FOR RETURNING CQNDENSATEWalter M. Simpson, Evansville, Ind., assignor to Serve], Inc, New York,N. 1., a corporation of Delaware Application March 1, 1952, SerialNo.'274,318

3 Claims. (Ci. 62-119) The present invention relates to refrigerationand'more particularly to improvements in apparatus of the type describedand claimed in a copending application for United States Letters Patentof Harry C. Shagaloif Serial No. 254,530 tiled November 2, l95l andentitled Refrigeration.

The Shagaloif invention relates broadly to a combination with a heatoperated refrigeration system having a cooling water circuit of anauxiliary apparatus utilizing the flow of cooling water to produce asuction for returning condensate from a heat receiving element of thesystem to a steam generating boiler and treating the cooling water withflue gas to reduce the formation of scale on the heat transfer surfaces.the Shagaloif invention relates to an intermittentlyoperating apparatuswhich first lifts condensate to a reser- More specifically,

voir vessel above the boiler and then discontinues the lifting ofcondensate and opens communication between the vessel and boiler for thegravity flow of condensate thereto. The separate steps of first liftingcondensate and then delivering lifted condensate to the boiler iscontrolled by a clock operated valve arrangement.

One of the objects of the present invention is to providean improvedapparatus of the type indicated which operates continuously to liftcondensate from the heat receiving element, return lifted condensate tothe boiler and supply a controlled amount-of flue gas to the coolingwater.

Another object is to provide an apparatus of the type indicated whichmaintains a pressure balancing liquid' column in a standpipe extendingupwardly from the boiler so thatcondensate will how to theboiler bygravity simultaneously with the supply of additionalcom densate to thestandpipe above the pressure balancing liquid column.

Still another object is to provide an apparatus of the' type indicatedwith an automatically operable valve responsive to the Weight of theliquid column in the standpipe to permit the how of condensate to theboiler while' reventingflow from the boiler to the standpipe.

Theseand other objects will become more apparent from the followingdescription and drawing in which like reference characters denote likeparts throughout the several views; it is to be expressly understood,however,

that the drawing is for the purpose of illustration only and not adefinition of the limits of the invention, reference being had for thispurpose to the appendedclaims in the drawings:

Fig. l is a diagrammatic view' of an air conditioning unit incorporatingthe auxiliary apparatus of the pres- Fi g. 2 is an enlarged sectionalview of an automatically operable valve for controlling liquid flowbetween a pressure balancing liquid column and steam generating boiler;and

Fig. 3 is an enlarged sectional view 'of a restricting" ice valve in theflue-gas conduit for controlling the flow of flue gas into the coolingwater.

Referring to Fig. l of the drawings, the present invention is shownapplied to an air conditioner for either cooling the air in the summerorheating air in the winter. The air conditioner comprises a source ofheat illustrated in the form of a steam boiler 6, a heat operatedrefrigeration system 7, a heating system 8, a selective valve 9 fordirecting steam from the boiler to the heatingsysterh or refrigerationsystem, respectively, and a cooling tower 10.

Boiler 6 may be of any suitable type such as the sectional cast-ironboiler illustrated and may be heated by anysuitable fuel burner such asthe gas burners 11. The sections of theboiler 6 are enclosed in a casingor hood 12 having an outlet pipe'lii and the hood and outlet pipe formadue 14 for the products of combustion. The heat from the flame andproducts of combustion is transmitted' through the walls of the boilersections to heat the water'therein to generate steam. Steam from theboiler 6 flows through a steam pipe 15 to chamber 16 of selective valve9 and a valve element 17 in the chamber directs the steam through aconduit 18 to the refrigeration system 7 or through a conduit 19 to theheating system 8. i

The heat operated refrigeration system 7 is shown in Fig. l' as anabsorption system of the type illustrated and' desc'ribed in UnitedStates Letters Patent to Albert R. Thomas et al. 2,282,5031ssued May 12,1942 and entitled Refrigeration. Such an absorption refrigeration Tsystem'operates in a partial vacuum and utilizes a refrigerant such aswater and a liquid absorbent such as a solution of lithium bromide. Therefrigeration system comprises a generatorZi), condenser 21, evaporator22, absorber 23 and heat exchanger 24 interconnected for the flow ofrefrigerant and absorbent. Generator 20 has at least one vaporliquid-lift tube 25' connected between a lower inlet chamber 26 and anupper separating chamber' 27 and thelift tube is enclosed in a jacket 28providing a heating chamber 29 therebetween. The heat of thesteamsupplied to the heating chamber 29 is transmitted through the wall ofthe lift tube 25 to expel refrigerant vapor from absorption solutiontherein and lift the solution into the separating chamber 27 byvaporlift action." v

Vapor fromthe separating chamber 27 flows through the conduit 36 to thecondenser 21. The condenser 21 is illustrateddiagrammatically ascomprising a chamber 31 having'a cooling coil 32 therein. Liquidrefrigerant from the chamber 31 of condenser 21 flows by gravity througha pipe 33 into the top of evaporator 22 illustrated in the form of aserpentine coil having spaced heat transfer fins 34. Pipe .33 may itselfcontrol the fiow'of refrigerant therethrough or may have a suitable flowcontrol means therein to maintain a difference in pressure between thecondenser 21 and evaporator 22. Refrigerantvapor from the evaporatorcoil 22 flows to the absorber 23.' The absorber 23 is in the form of ahermetically sealed shell or casing 35 having heat transfen-coils 36therein and liquid distributing means 37 overlying the coils fordistributing absorption liquid for gravityflow over the coils;

Simultaneously With'the flow of refrigerant vapor to the condenser'21,absorption solution weak in refrig-' of the refrigerant, water, for theabsorption solution,

lithiumbromide, the refrigerant evaporates in the evaporatdrZZat' a lowpressure and temperature to produce a refri g'efating- 'effect and therefrigerant vapor is ab-" sc-rbed in the absorption solution as fast asit is formed in the evaporator. The absorption solution strong inrefrigerant flows by gravity from the absorber 23 to the inlet chamber26 of generator 29 in a path of flow inciuding conduit 41, inner passage42 of liquid heat exchanger 24 and conduit 43.

The heating system 8 comprises a radiator 45 having spaced headers withfinned tubes 43 extending between the headers. The steam conduit 19 fromthe selective valve 9 is connected to one of the headers 47 and steamflows through the tubes 48 in parallel and condensate returns throughthe lowermost tube and conduit 19 back to the selective valve 9. Boththe heating chamber 29 for the generator 29 of the refrigeration systemand a header 47 of the heating system are vented to the atmosphere by acommon vent pipe 4-9 to maintain the steam from the boiler 6 atatmospheric pressure. Condensate drains from chamber 16 of selectivevalve 9 back to boiler 6 through a conduit 56 and condensate is returnedfrom the heating chamber 29 of generator 2% by apparatus later to beexplained in detail.

Cooling tower is usually located at a place remote from therefrigeration unit and may be of any suitable construction. Asillustrated, the cooling tower is generally similar to that illustratedand described in my prior United States Letters Patent 2,562,827 issuedJuly 31, 1951. Sulfice it to state herein that the cooling towercomprises an upright casing 52 having a fan 53 at the top of the casing,a sump 54 at the base of the casing, packing 55 in the intermediateportion of the casing, distributing nozzles 56 between the fan and thepacking and a water makeup valve 57 in the sump. A pump 58 at the baseof cooling tower 10 draws water from sump 54 through a filter 54a andcirculates it in a circuit through the cooling coils 36 of absorber 23and cooling coil 32 of condenser 21. The circuit comprises a conduit 59connected between the outlet from the pump 58 and a water operatedaspirator 60, later to be described in detail, a conduit 61 connectingthe outlet end of the aspirator to one end of the cooling coil 36 inabsorber 23, a conduit 62 connecting the outlet from the cooling coil 36to one end of the cooling coil 32 of condenser 21 and a conduit 63connecting the opposite end of the condenser cooling coil 32 to thenozzles 56 in the cooling tower.

While the apparatus thus far described is illustrated diagrammaticallyin Fig. l, the commercial apparatus has all of the elements of thesystem mounted on a frame to provide a self-contained unit. To conservespace and maintain the overall height of the unit to a minimum theboiler 6 and generator are both located on the base of the frame so thathe bottom of the heating chamber 29 is located below the liquid level Lin the boiler 6 as shown in Fig. 1.

Auxiliary apparatus also is provided which utilizes the flow of water inthe cooling water circuit to produce a force for lifting condensate fromthe heating chamber of the refrigeration system for gravity return tothe boiler. Preferably, the same force is also utilized to inject fluegas into the cooling water to reduce or prevent carbonate scale fromforming on the heat transfer surfaces. The apparatus comprises theaspirator 60 which draws gas from a source at atmospheric pressure,preferably flue gas from the boiler, and utilizes the flow of the fluegas to lift condensate from the heating chamber of the refrigerationsystem to a level above the boiler. As thus far described, the apparatusis the same as disclosed in the copending Shagaloff application,referred to above.

In accordance with the present invention, the auxiliary apparatus is soconstructed and arranged as to continuously lift condensate from theheating chamber 29 of the heat receiving element or generator 20 of therefrigeration system 7 to a level above the liquid ievel L in boiler 6and continuously deliver lifted condensate to the boiler. The apparatusmaintains a pressure balance liquid column iz above the liquid level inthe boiler 6 so that additional condensate supplied at the top of theliquid column will cause a corresponding amount of condensate to bedelivered from the bottom of the column to the boiler by gravity. Anautomatically operated valve 64 is also provided which prevents the flowof liquid from the boiler to the pressure balancing liquid column but isresponsive to the weight of additional condensate supplied to the top ofthe column to open the valve and permit flow from the column to theboiler.

in Fig. l. of the drawings the auxiliary apparatus is shown ascomprising a standpipe 65 having its lower end connected to the boiler 6below the water level L therein. The standpipe 65 extends upwardly to aheight above the liquid level L in the boiler to maintain a pressurebalancing liquid column h therein and is enlarged at its upper end toprovide a reservoir vessel 66 for a purpose as will later appear. Thetop of the reservoir vessel 66, constituting the upper end of standpipe65, is connected to the aspirator by a suction line 67 having arestricting valve 68 therein. A gas operated liquid-lift 69 is connectedbetween the bottom of the heating chamber 29 of generator 20 and thereservoir vessel 66 of standpipe adjacent the top thereof. The gasoperated liquid-lift 69 comprises a sump 7t) and lift tube 71. Sump 76is connected to the bottom of the heating chamber 29 by a conduit 72 andconnected to the hood 12 of boiler 6 by a flue gas line 73. Lift tube 71has its lower open end 74 projecting into the sump to a positionadjacent the bottom thereof and its upper curved end 75 projectingthrough the side of the reservoir vessel 66.

The automatically operable valve 64 which controls the flow of liquidbetween the boiler 6 and standpipe 65 is located in the standpipeadjacent the liquid level L.

' Valve 64 is shown in detail in Fig. 2 as comprising a valve housing 77having a valve seat 78. A suitable ball type valve element 79 isprovided in the housing 77 for engage- .ment with the seat 78 whenliquid tends to flow from boiler '6 toward the standpipe 65 to close thestandpipe. However, the valve element 79 is moved away from seat 78 inresponse to the weight of liquid above a pressure balancing column It ofliquid in the standpipe 65 to open the standpipe 65 for the flow ofcondensate to the boiler 6. A stop 80 in the valve housing 77 holds thevalve element '79 from movement toward the opposite end of the housingwhile providing a space between its periphery and the housing for theflow of liquid from the standpipe 65 to the boiler 6.

' The restricting valve 68 in suction line 67 is shown in detail in Fig.3 as comprising a valve housing having a restricting seat 86 withgrooves 67 at one end and a sealing seat 88 at its opposite end. Asuitable ball type valve element 89 in the housing 85 engages valve seat86 when the direction of flow is toward the aspirator 60 and engagesvalve seat 83 when the direction of flow is toward the reservoir vessel66. Restricting grooves 87 in seat 86 permit the flow of only the amountof flue gas to the aspirator 60 and cooling water required to controlthe precipitation of mineral carbonates from the water and the formationof scale on the heat transfer surfaces. The engagement of the valveelement 89 with the seat 88 prevents the flow of cooling water to theboiler 69 under any conditions as when the conduit 59 from the coolingtower 10 is located above the aspirator 60. One form of the inventionhaving now been described, the mode of operation of the completeapparatus is explained as follows.

To initiate operation of the air conditioning unit, the fuel burners 11are ignited to heat the boiler 6 and generate steam therein. Whenheating is desired the valve element 17 of the selective valve 9 isshifted to close conduit 18 to the refrigeration system 7 and openconduit 19 to the heating system 8. Steam then flows from the boiler 6through the conduit 19 to one of the headers 47 of the radiator 45 andthen through the fin tubes 48 between the headers. Air directed over thefin tubes 48 is heated and the 'cond en'sate from'the radiatonreturns'through the conduit 19 to the charhber'of the selective valve 9 and fromthere back to the-boiler 6 through the condensate return conduit 50.

Whencooling or dehumidification is desired, the valve element 17 of theselective valve'9 is actuated to close conduit 19 to the'heating system8 and open the conduit 18 to the refrigeration system 7. -Steamthen'fiowsfrom the boiler 6 through the conduit 18 to the heatingchamber 29 of the generator 20. The heatfrom the steam is transmittedthrough the lift tube to expel refrigerant vapor fromabsorption solutionwhich,-during its fiow through the system, produces refrigeration in theevaporator 22 and the-heating steam "is condensed in the generator 20and flows by gravity to the'bottom'of the heating chamber 29.

Simultaneously with the supply of steam from boiler 6 to generator 20,operation of the cooling tower 10 is initiated and pump 58 circulatesWater through the cooling water circuit. Cooling water from the coolingtower sump 54 is delivered under pressure by pump 58 for flow throughconduit 59, aspirator 60,'conduit 61, cooling coils 36 in absorber 23,conduit 62, cooling coil 32 of condenser 21 and conduit 63 back to thenozzles 56 in the cooling tower. Water is sprayed from the nozzles 56onto the packing where it flows by gravity in thin sheets toward thesump 54 and is contacted by air flowing in the opposite direction. Theair and liquid contact causes evaporation of a portion of the water toreduce its temperature and the cooled water accumulates in the sump 54where it is again recirculated through the cooling water circuit. Theflow of cooling water through the coils 36 and 32 of the absorber 23 andcondenser 21 in succession removes the heat of absorption andcondensation from the refrigeration system 7.

On the initial start-up of the air conditioning apparatus the flow ofcooling water through the aspirator 68 will produce a suction to drawflue gas from the hood 12 of the boiler 6 through the flue gas line 73,lift tube 71, standpipe and suction line 67 but with very littlereduction in pressure in sump 70. After steam has been generated in theboiler 6 it will flow at a constant rate to the heating chamber 29 ofgenerator 20 and condensate will be delivered through the conduit 72 tothe sump at the same constant rate. Condensate will accumulate in thebottom of the sump 70 until it seals the lower end 74 of the lift tube71. As the aspirator 6) withdraws gas from standpipe 65, a suction willbe produced in lift tube 71 and draw condensate from sump '76 into thelift tube. The withdrawal of a small amount of condensate from sump 70will again uncover the lower end 74 of lift tube 71 and draw in flue gasuntil the liqui level in the sump again seals the lower end of the lifttube. Thus, condensate is continuously lifted through the lift tube 73in interrupted slugs with flue gas therebetween. As the rate at whichcondensate is supplied to sump 70 and as the rate at which the aspirator60 draws in gas are substantially constant, an equilibrium condition issoon attained at which the relative lengths of the slugs of condensateand flue gas in the column and the weight of the column aresubstantially constant.

The condensate and flue gas will be delivered continuously at asubstantially constant rate from the upper end of the lift tube 71 intothe vessel 66 of standpipe 65 and the flue gas flows through the suctionline 67 and restricting valve 68 to the aspirator 60 and then into thecooling Water. During the initial period of operation of the airconditioning unit the condensate will accumulate in the standpipe 65until a solid column of the condensate has been formed of a height h tobalance the difference in pressure between the standpipe 65 at the topof the column and the atmospheric pressure in the boiler 6 and theweight of the solid column of condensate in standpipe will equal theweight of the column of condensate and flue gas in lift tube 71. Duringthe tim'e that the liquid column is being-'forme'din standpipe65,"'valve 64 prevents the flow of liquidfrom the boiler 6 to thestandpipe. After a pressure balancing amount of condensate to theboiler'-6. 'As condensate is being supplied to the reservoir vessel 66continuously at a substantially constant rate or, in other words, asfast as it is condensed in the heating chamber 29 of generator 2tcondensate will flow continuously from the standpipe 65 to the boiler 6.

During ofi cycles of the air conditioning unit the coolin g tower pump58 will be stopped which, in turn, will stop operation of aspirator 60."At the beginning .of the next on period of operation of the airconditioningunit condensate may have accumulated in the lower end ofthe-heating chamber 29 and in the sump 70. Under-such conditions theaccumulated condensate may be lifted in a solid stream-through the lifttube 75 but the enlarged- 1 reservoir vessel 66 in the standpipe 65 willaccommodate such surplus condensate without rising above the height ofliquid column h before normal operation is restored. Valve 64 willprevent the flow of liquid from the boiler 6 to the standpipe 65 so thatthe space in the vessel 66 above the liquid level is available for theaccumulation of such surplus condensate before the lift tube 71 startsto suck flue gas. At all times during operation of the cooling waterpump 58, flue gas will be delivered at a controlled rate to the coolingwater.

It will now be observed that the present invention provides an improvedapparatus for continuously lifting condensate from the heat receivingelement of the refrigeration system and continuously returning thelifted condensate to the boiler. It will still further be observed thatthe present invention provides a standpipe connected to the boiler andso constructed and arranged as to maintain a pressure balancing liquidcolumn of condensate between the boiler and the gas operated liquid liftso that additional condensate supplied to the standpipe will cause flowof a corresponding amount of condensate to the boiler. It will stillfurther be observed that the present invention provides an automaticallyoperable valve in the standpipe which is responsive to the Weight of thecolumn of liquid in the standpipe to control the flow of condensate tothe boiler.

While a single embodiment of the invention is herein illustrated anddescribed, it will be understood that changes may be made in thestructure and arrangement of elements without departing from the spiritor scope of the invention. Therefore, without limitation in thisrespect, the invention is defined by the following claims.

I claim:

1. In a heat operated refrigeration system having a heat receivingelement, a heat rejecting element, means for flowing cooling water inheat exchange relation with the heat rejecting element and a boiler forproducing vapor for heating the heat receiving element, the combinationwith the elements of said system of apparatus utilizing the flow ofcooling water for simultaneously returning condensate from the heatreceiving element to the boiler and treating the cooling water with fluegas consisting of a standpipe extending above the liquid level in saidboiler, a sump connected to receive condensate from the heat receivingelement and flue gas from the boiler, a vapor liquid-lift connecting thesump and standpipe, an aspirator in the means for flowing cooling waterand connected to the standpipe adjacent the top thereof, and a singlevalve in the standpipe having a movable element automatically operatedby a differential force at opposite sides of the element.

2. In a heat operated refrigeration system having a heat receivingelement, a heat rejecting element, means for flowing cooling water inheat exchange relation with the heat rejecting element and a boiler forproducing vapor for heating the heat receiving element, the combi nationwith the elements of said system of apparatus utilizing the flow ofcooling water for simultaneously returning condensate from the heatreceiving element to the boiler and treating the cooling Water with fluegas consisting of a standpipe extending above the liquid level in saidboiler, a sump connected to receive condensate from the heat receivingelement and flue gas from the boiler, a vapor liquid-lift connecting thesump and standpipe, an aspirator in the means for flowing cooling waterand connected to the standpipe adjacent the top thereof, and a checkvalve in the standpipe automatically operable to prevent flow from theboiler to the standpipe and permit flow from the standpipe to the boilerwhen the weight of the column of liquid in the standpipe exceeds theforce on the boiler side of the valve.

3. In a heat operated refrigeration system having a heat receivingelement, a heat rejecting element, means for flowing cooling water inheat exchange relation with the heat rejecting element and a boiler forproducing vapor for heating the heat receiving element, the combinationwith the elements of said system of apparatus utilizing the flow ofcooling water for simultaneously returning condensate from the heatreceiving element to the boiler and treating the cooling water with fluegas consisting of a standpipe extending above the liquid level in saidboiler, a sump connected to receive condensate from the heat receivingelement and flue gas from the boiler, a vapor liquid-lift connecting thesump and standpipe, an aspirator in the means for flowing cooling waterand connected to the standpipe adjacent the top thereof, a check valvein the standpipe having a valve seat and a ball element engaging thevalve seat to prevent flow from the boiler to the standpipe, and saidball being automatically actuated by the weight of a liquid column inthe standpipe to permit flow from the latter to the boiler.

References Cited in the file of this patent UNITED STATES PATENTS1,263,845 Broman Apr. 23, 1918 2,349,396 Andersson May 23, 19442,375,406 Drown May 8, 1945 2,515,319 Sherwood July 18. 1950

1. IN A HEAT OPERATED REFIGERATION SYSTEM HAVING A HEAT RECEIVINGELEMENT, A HEAT REJECTING ELEMENT, MEANS FOR FLOWING COOLING WATER INHEAT EXCHANGE RELATION WITH THE HEAT REJECTING ELEMENT AND A BOILER FORPRODUCING VAPOW FOR HEATING THE HEAT RECEIVING ELEMENT, THE COMBINATIONWITH THE ELEMENTS OF SAID SYSTEM OF APPARATUS UTILIZING THE FLOW OFCOOLING WATER FOR SIMULTANEOUSLY RETURNING CONDENSATE FROM THE HEATRECEIVING ELEMENT TO THE BOILER AND TREATING THE COOLING WATER WITH FLUEGAS CONSISTING OF A STANDPIPE EXTENDING ABOVE THE LIQUID LEVEL IN SAIDBOILER, A SUMP CONNECTED TO RECEIVE CONDENSATE FROM THE HEAT RECEIVINGELEMENT AND FLUE GAS FROM THE BOILER, A VAPOR LIQUID-LIFT CONNECTING THESUMP AND STANDPIPE, AN ASPIRATOR IN THE MEANS FOR FLOWING COOLING WATERAND CONNECTED TO THE THE STANDPIPE ADJACENT THE TOP THEREOF, AND ASINGLE VALVE IN THE STANDPIPE HAVING A MOVABLE ELEMENT AUTOMATICALLYOPERATED BY A DIFFERENTIAL FORCE AT OPPOSITE SIDES OF THE ELEMENT.